Coded switch system for towling conveyors



Oct. 22, 1968 E. c. BRAUN 3,406,533

I CODED SWITCH SYSTEM FOR TOWLINE CONVEYORS Filed Oct. 12, 1965 3 Sheets-Sheet l EDWIN C. BRAUN ATTORNEY Oct. 22, 1968 c, BRAUN CODED SWITCH SYSTEM FOR TOWLINE GONVEYORS 5 Sheets-Sheet 2 Filed Oct. 12, 1965 Oct. 22, 1968 E. c. BRAUN 3,

CODED SWITCH SYSTEM FOR TOWLINE CONVEYORS Filed Oct. 12, 1965 3 Sheets-Sheet 3 FIG. IO

United States Patent 3,406,638 CODED SWITCH SYSTEM FOR TOWLINE CONVEYORS Edwin C. Braun, Smithsburg, Md., assignor to Aerojet- General Corporation, El Monte, 'Calif., a corporation of Ohio Filed Oct. 12, 1965, Ser. No. 495,112

Claims. (Cl. 104-88) ABSTRACT OF THE DISCLOSURE This invention relates to towline systems of the kind generally shown in my previous application, S.N. 410,215, filed Nov. 10, 1964, now Patent No. 3,315,614, and SN. 420,322, filed Dec. 22, 1964. p i

In general, such towline systems comprise carts which are moved across a floor for carrying cargo, the motive power being provided by towline cables or chains below the floor, wherein each cart hasa towline pin protruding through a slot in the floor to engage the towline. Various systems comprise switch junctions so that selected carts can be switched from a main slot to a spur slot for cargo discharge or cart storage, etc.

In the present invention, a switch junction mechanism is disclosed capable of effecting predetermined switching from one slot to another, dependent upon control by code pin members carried by individual carts.

The particular feature of the present invention is the provision of a movable switch frog which is controlled by the actuation of selectively positionable movably mounted sensing members. Such members are rockably supported in a common mechanism which is installed in a floor on which carts roll and are engaged by pins carried by carts.

The members may be placed in preset coded positions to be engaged by correspondingly coded pins. In that manner the coding of pins coacting with coded members (referred to as sensing tabs) can be utilized for a plurality of switch locations, each location having its respective coding of sensing tabs for controlling'a switch frog at such location when the tabs are engaged by properly coded pins of aspecific cart.

Thus, the support mechanism comprises a frame insertable in a floor adjacent a switch junction wherein such frame may take various forms but wherein any such frame is capable of holding a plurality of sensing tabs in selected positions for any desired predetermined coding.

It is, accordingly, an object of the invention to provide a system in which predetermined switching of carts at selected junctions can be effected in a simple and reliable manner.

It is another object of the invention to provide an economical and rugged construction for elfecting a switching system and one which will be convenient inuse.

It is a still further object of the invention to provide a system in which individual carts can carry a coded means coactingwith a coded means at a selected switch junction wherein the cart and junction coding means are variable so that any cart of a series of carts canjbe switched selectively to any junction.

It is an even further object of the invention to provide a coding system for switching control so that a vast number of switch junctions can be provided in any one towline system operating over a large area such as a factory floor, warehouse, post office, or transportation depot, etc.

Briefly, the invention comprises a coding means carried by each cart wherein two pins are carried in variable predetermined positions and which are engageable with correspondingly positioned sensing tabs located adjacent a selected switch junction. The sensing tabs are likewise selectively variable as to their relative Positions.

7 The arrangement is such that each of a pair of codedly positioned pins must strike respective sensing tabs in order to operate a elected switch. If only-one pin strikes a tab, the switch will not be operated. The result is that a cart in which both pins have not been coded to correspond to the sensing tab positions will continue past the switch junction without being diverted. Any cart, however,

wherein the pins have been coded .to simultaneously strike or engage the coded tabs will cause movement of a switch frog to divert the cart towpin from the slot in which it is moving to a spur slot ora different towline loop of the system. j, j

A detailed description of the invention now follows in conjunction with the appended drawing, in which:

FIG. 1 is a perspective view showing fundamental components of the combination of the invention; A

FIG. 2 is a plan view showing details of a switch junction;

FIG. 3 is a perspective view showing the relative positions and supporting structure of a pair of sensing tabs;

FIG. 4 is a perspective view showing the relative position of the actuating elements for a switch frog;

FIG. 5 is a longitudinal cross section in elevation showing the general constructional details of a switch junction box taken generally on the section line 55 of FIG. 1;

FIG. 6 is a fragmentary plan view partially in section with portions broken away to show detail, taken generally on the section line 66 of FIG. 5;

FIG. 7 is a plan view of a fragment of the construction showing a corner of the switch junction;

FIG. 8 is a perspective showing the fundamental components of a modified version of the invention insofar as the sensing tabs are concerned;

'FIG. 9 is a perspective showing a switch frog and actuating elements controlled by the tab arrangement of FIG. 8;

FIG. 10 is a section in elevation taken on section line 10-10 of FIG. 9; 7

FIG. 11 is an elevational view partially in section showing a modification wherein the sensing tabs operate electrical switches to control a switch frog; and

FIG. 12 is a perspective illustrating the fundamental components for electrical operation of a switch frog.

Referring now to FIGS. 1-4, the invention comprises a cart C of conventional construction movable on a floor F, being guided in a slot S through which the towpin T protrudes for engagement with a towline chain K, all in the usual and conventional manner. A switch junction J is indicated operative to switch towpins from slot K to a spur or side loop slot S. It will be understood that the construction of the towlines below the floor, and their coaction with each other, are such that the cart towpins can be disengaged when a cart is switched or diverted from a towline such as K to a towline such as K, e.g., as shown in my co-pending application S.N. 420,322. In some instances, where carts are merely being stored in a slot S, there would be no need for a towline K, 'but where S represents entrance to another loop of the system, then it is obvious that a towline K would be used. The mode of disengagement and engagement of the towpin does not form part of this invention and can be accomplished by means heretofore known in the art or as disclosed in the art or as disclosed in the previously mentioned application.

The invention is characterized by the provision of an apertured bracket 10 for carrying a plurality of code pins such as 12 and 15, which can be placed in a selectively coded manner in any pair of the bores 18 of bracket 10.

The bores 18 are provided in' plurality in a pair of parallel rows, but it will be appreciated that any pattern of bores is within the spirit of the invention. Thus, each cart would carry a bracket and one or more code pins to engage one or more sensing tabs such as 22 and 25, which are located at the switch junction J. Although ordinarily thesystem is intended to utilize a pair of code pins in the present disclosure, it will be appreciated from what follows that systems using a single code pin or more than two code pins are .quite possible.

Referring to FIG. 2, the switch frog 30 is noted carried by a pivot pin 33, which frog diverts movement of towpins T from slot S to slot S, indicated by the phantom line position of the frog. Thus, with the switch frog in the solid line position the towpin proceeds in the slot S, whereas with the switch frog in the phantom line position the towpin is diverted into the slot S, following the arrows. It Will be noted that the switch frog has a cam edge 36 projecting into slot S when the frog is in the switching position and, accordingly, a diverted towpin can engage that edge to swingthe frog back to the full line position whence slot S is once more open and slot S closed. The floor pieces 40, 43, and 46 will be understood to be made of metal (also see FIG. 1) and suitably notched as at 49 and 52 to provide clearance for the upstream end 54 of the frog 30.

Referring to FIG. 3, the sensing tabs 22 and 25 are carried in respective slots 60 and 63 of respective rotative elongated holders 67 and 70 having trunions such as 73 carried in side plates 75 fastened at their upstream ends by an angle iron 78 and being provided with bores 81 at their downstream end so that hte entire sub-assembly which comprises the sensing tabs and holders can rock on a horizontal axis as an integral frame 82 (FIGS. 3 and The plates 75 are connected downstream of the sensing tabs by an angle iron 84 and, accordingly, it will be understood that a box-like bracket construction results which pivotally supports the assembly of holders 67 and 70 and respective sensing tabs 22 and 25, the holders themselves being individually pivotal in side plates 75. Parallel plates such as 87 are weldedspacedly to the angle iron members 78 and 84 and are utilized as side guards for the sensing tabs and as floor members when depressed by wheels W (FIG. 1) and also to divide the holders into pockets into which tabs may be selectively placed for coding purposes. Thus, a tab may be annually slid into a slot between any two guards 87, whereby coding of the tabs at any switch junction can be effected to align a pair of tabs for engagement with a pair of correspondingly coded pins such as 12 and 15 (FIG. 1). Guards 87 have been omitted in FIG. 1 for clarity but are depressible simultaneously upon engagement of cart wheels against sloping front edges 87a.

A feature of the invention resides in the ease with which the tabs may be removed from any coded positions for re-coding in other compartments of the arrangement at any switch junction, the tabs being held frictionally in respective slots.

It will be apparent from the above description that coded pins striking respective coded tabs will cause respective holders 63 and 67 to rock counterclockwise, as viewed on FIGS. 1 and 3, the ends of the pins simply sliding past the top edges of the tabs as the cart moves beyond the tabs.

The angle iron 84 carries a stop element 90 in the form of an angle having an edge 93 and another edge 96, FIGS. 3, 5 and 6. The bracket 67 carries an actuator lever 100 and the holder 70 carries an actuator lever 103. These levers terminate below the level of respective edges 93 and 96 and have fastened thereto actuator cables or chains such as cable 106 fastened to lever 100 and cable 110 fastened to lever 103. The cables are maintained under tension and are disposed in a horizontal plane, compression springs being used for maintaining tension, as noted in FIG. 4. Thus, the spring 113 efiects tension in cable 106 and the spring 116 efiects tension in cable 110.

The effect of the springs is to maintain the respective levers 100 and 103 in abut-ment with respective edges 93 and 96 of the stop member 90 so that the respective tabs 22 and 25 are normally disposed in substantially vertical planes. However, as described above, when the code pins strike the tabs, they effect rocking thereof by virtue of the pivotal holders 67 and 70. Accordingly, cables 106 and 110 are pulled to the right as viewed on FIGS. 3 and 4. As seen on FIG; 4, the cables are attached to respective latch pins' 118 and 121 "which are carried in a housing 124 being reciprocally. supported therein on plates 127 and 130. The springs 113 and 116 are carried concentrically on respective latch pins "and are stressed between pins such as 132 and plate-127 to maintain tension in cables 106 and 110. 7 The pins 118 and 121 extend into engagement at their free extremities with a latch plate 135 which is firmly secured to 'pivot pin 33 (see FIG. 4) on which is mounted the frog plate 30. Extending from the latch plate 135 is an arm 138 and a tension spring 141 is fastened between the arm and a tongue 143 extending from support plate 127. Spring 141 maintains a bias on the frog to open switch position, shown in, phantom lines in FIG. 2. Normally, latch pins 118 and 121 are engaged by plate 135 to hold the frog in closed switch position as shown in solid lines in FIG. 2. Should the latch pins be pulled to the right, plate 135 will swing under bias of spring 141 closing slot S by means of frog 30 and opening slot S.

When tabs 22 and 25 are rocked by the code pins, they pull the latch pins via the respective cables 106 and 110 to release latch plate 135. Obviously, both pins 12 and 15 must engage their respective tabs 25, 22, so that both latch pins are pulled out to release the latch plate and thus cause frog 30 to move to the phantom line postion of FIG. 2, thus diverting carts to slot S.

It will be understood at this point that the system could be coded for use with a single latch pin and a single code pin acting against a single tab. However, the use of two code pins considerably increases the permutations with which the system can be used for controlling a plurality of switch junctions. Likewise, the use of more than two code pins would further increase the number of permutations. Modification of the latching arrangement and tab arrangement for more than two code pins would be a mere matter of duplication of the necessary components.

The free ends of rods 118 and 121 protrude only a small distance beyond the adjacent end of latch plate 135 and the dimensioning of the frog and the towline slots is such that the latch plate only swings a short distance. In actual practice, the swing distance may be of the order of one-half inch. Accordingly, the pins 118 and 121 do not escape past the edge'of plate 135 but merely remain'abutted thereagainst as indicated in phantom in FIG. 4. Were they to escape past the edge they would block latch plate 135 from efiecting a reset movement to return position.

In reset, the towpin simply pushes the edge 36 to swing the frog 30 into the closed position of FIG. 2 from the dotted-line position. In so doing, the latch pins merely snap back to the position shown in FIG. 4

' under bias of springs 113 and 116 whence latch plate is once more held against movement until another pair of properly coded code pins strikes the sensing tabs.

Referring to FIGS. 57,'the housing 124 is secured within a floor box which may be of any suitable construction and sunk into a floor so that the plates 43, 46 are flush at floor level. Various supporting elements, such as angle irons 155, 158, and may be utilized for rigidifying the construction and the design of the floor box, all matters well within the skill of persons in the art. Accordingly, no detailed discussion of the box construction is required for the purposes of a clear understanding of the invention.

The tab carrying assembly, or tab carrier, comprised of plates 75 and slotted rocker bars '70, angles 78, 84, etc., may be pivoted between and to vertical pedestals 164 (FIG. 5) as by pins 161, 166 extending into apertures 81 of plates 75. The angle iron 78 has a yoke 170 secured thereto which engages against a washer 173 supported by a compression spring 176 concentric with a guide pin 179 securely fastened at its base 182 to a corner of the floor box. A cable 185 fastens to an eye 188 secured to angle iron 78, and passes around pulley 192 (FIG. 5) extending through guide tube 195 (FIG. 7) suitably secured near the box floor. Pulling the cable will swing the bracket around pins 167 to lower the tabs below fioor level, against bias of spring 176, so that the tabs cannot be engaged by code pins of carts. This prevents overload of spur slots and pulling of the cable may be accomplished in a manner shown in the patent to Bradt et al. 3,103,895.

A threaded limit stop means 197 may be utilized abuttable with either or both of the carrier plates 75 for limiting maximum downward movement of the carrier. Thus, if the frame 82 is depressed either'by cable 185, or by cart wheels, the lower edge of one or both plates 75 strikes a limit stop 197 to limit downward swinging of the carrier so that frame 82 is supported with edges 198 of plates 87 flush with floor plate 46 to effectively bridge the large slot 199 (FIG. 5) through which the tabs protrude to provide a floor surface over which the cart wheels can travel as they depress the guards upon engaging the sloped front edges 87a.

Referring to FIGS. 8-10, the modification therein contemplates sensing tabs 22 and as in the previously described modification, carried in the rocker bars 67 and 70 with levers 100 and 103. In this instance, however, a single cable 200 (FIG. 9) extends from the sensing mechanism and passes around a roller sheave 205 carried on an arm 208 which in turn carries integrally frog on a pin 210. Pin 210 is supported for rotation in a support channel 215 which will be understood to be secured in a floor box the equivalent of the housing 124 of the previously described modification. The cable ends are tensioned as shown in FIG. 8 as by tension springs 218 secured to each side of the cable, such tension springs being fixed at their outer ends. It will be appreciated that if the tabs of FIG. 8 are actuated to rock counterclockwise, as by code pins, both sides of the cable will pull equally against sheave 205 causing arm 208 to rotate counterclockwise, whereby the frog 30 will rotate accordingly around the axis of pin 210 to the open switch position illustrated in FIG. 2. A detent arrangement is utilized to hold the frog in closed or open switch condition. Thus, a spring-holding collar 220 containing a compression spring 222 is carried below arm 208 and the spring presses a ball 225 into either of the two notches 227 or 230 on the under side of the arm. Accordingly, the frog will be held in switch open or switch closed condition. Upon reset, when the towpin strikes the edge 36 of the frog the arm will swing to snap the ball from one detent notch to another. In'the position shown, the ball is in switch open position. When the arm swings to the dotted position shown in FIG. 10, the ball will go into notch 227 to hold the frog in frog open position. The notch and ball arrangement must, of course, provide sufiicient detent elfect so that the arm will be held against the pull of springs 218 when the frog is in either position. When the frog has been moved to switch closed position, the springs pull the tab holders to hold the tabs vertically as shown in FIG. 8.

In the form of the invention shown in FIGS. 11 and the usual manner as heretofore described on apin 250 carried in a support bracket 255. Pin 250 has an arm 258 spring tensioned as by a spring 261 to open switch condition which condition is maintained by a latch plate 264 secured to pin 250 when engaged by a latchv pin 267 supported in plate 270. Solenoid 245 may be fixedly carried on support member in any suitable manner, and when energized, it will be understood to have a plunger connected to pin 267 which retracts the pin against a spring within the plunger bore, thereby releasing the frog to switch open condition. The edge of the plate 264 holds the pin while the frog is open and upon resetting actuation by the towpin against edge 36, the pin 267 is actuated by the solenoid spring back to latching position against plate 264. The energization of the solenoid is, of course, only momentary, occurring when the code pins engage and move past the sensing tabs.

What is claimed is:

1. A towline cart switching system having a switch junction installed in a floor; a cart provided with a plurality of code pins and support means carried by said cart whereby said code pins may be disposed in a predetermined relation to each other, a switch means at said switch junction having codable sensing elements and a common support mechanism in said floor for movable support of said sensing elements, and means whereby said sensing elements may be coded by being selectively positioned in said mechanism in relation to each other so as to be movably engaged by respective code pins; actuatable means connected to said sensing elements in said switch means whereby simultaneous actuation of said sensing elements by code pins efiects operation of said switch means to divert said cart at said switch junction.

2. A cart switching system having a switch juncture with diverging cart path means meeting thereat and comprising a movable switch element disposed to be moved in either of two positions, one such position for permitting carts to continue past said junction without being switched and the other such position to effect cart switching, means for biasing said switch element to one such position and latch means for holding said switch element in the other such position against the force of said bias means, a sensing means comprising sensing tab elements and a common mounting support frame means mounting said tab elements in predetermined positions with respect to each other operative for effecting selectively individual support for said tab elements for coding; means connecting said tab elements to said latch means whereby simultaneous movement of said tab elements from an initial predetermined position effects release of said latch means to permit said switch element to switch carts from one path to another.

3. A system as set forth in claim 2, including a cart having codable pin elements and means for supporting said pin elements on said cart in position to engage re-. spective sensing tab elements as said cart approaches said switch junction to effect release of said latch means.

4. In a system of the kind described, a cart sensing device for effecting the switch of carts at a switch junction, comprising a pair of elongated bar elements rockably supported in axial parallelism, a sensing tab for each of said bar elements and securing means for securing a respective sensing tab on its bar element at predetermined points along the length thereof and support means for locating said bar elements at a predetermined location relative to the switch junction.

5. In a system as set forth in claim 4, a switch element and means comprising latch elements for holding said switch element in a predetermined position and means connecting said bar elements with respective latch elements whereby movement of said sensing tabs efi'ects movement of said latch elements to release said switch element.

6. In a system as set forth in claim 4, wherein said connecting means comprises cable means and resilient means disposed to tension said cable means and to effect latching positions of said latch elements.

7. In a system as set forth in claim 5, said support means comprising a support device for said rockable bars and a motion limiting means carried by said support device comprising a member having a pair of stepped edges disposed below said bars, each of said bars having a lever secured thereto and abutable with a respective edge to limit rocking movement of respective bars for effecting an initial position of said tabs, said connecting means comprising a cable connected to each lever and extending to a respective latch element.

8. In a system as set forth in claim 5, said securing means comprising slots in said rocking bars, each of said rocking bars having at least one slot extending the length thereof and said sensing tabs comprising members insertable and removably securable in the slot of the respective rocking bar at selective positions.

9. In a system as set forth in claim 5, each of said rocking bars having a slot and said sensing tabs comprising members insertable and removably securable in the slot of the respective rocking bar, including a plurality of spaced vertical guard members and means for securing said guard members over said rocking bars in planes generally normal to the axes thereof and demarcating codable positions of said sensing tabs.

10. In a system as set forth in claim 5, and said support means for supporting said rocking bars comprising a support frame in which said bars are rockably supported, and means for rockably supporting said support frame, resilient means for holding said support frame in 'an initial position whereby said sensing elements may be engaged by moving actuator elements carried by a cart and means for retracting said frame against the resilient bias thereof, whereby said sensing tabs are moved therewith so as to prevent such engagement.

11. A towline cart switching system having a switch junction and a cart provided with a plurality of code pins and support means therefor whereby said code pins may be disposed in a predetermined relation to each other, a switch frog at said switch junction and sensing elements and support means for said elements at said switch junction whereby said elements may be disposed in relation to each other so as to be engaged by respective code pins; actuating means at said switch junction whereby actuation of said sensing elements effects operation of said switch frog to divert said cart at said switch junction, said switch frog being pivotally mounted and bias means to bias said switch frog to one position; latch means for holding said switch frog in another position against the force of said bias means, said latch means comprising a latch plate integral with said switch frog and further comprising a pair of pins having ends disposed to abut said latch plate at one side thereof to latch said switch frog against pivoting; said latch pins being movably mounted and spring means for said pins to maintain said pins in latching relation with said latch plate, and means connecting respective pins to said sensing elements whereby movement of said sensing elements Withdraws said pins from latching relation with said latch plate thereby releasing said switch frog to assume a position effected by said bias means, and means for limiting movement of said switch frog so that said latch plate does not travel beyond the ends of said pins.

12. A towline cart switching system having a switch junction and a cart provided with a plurality of code pins and support means therefor whereby said code pins may be disposed in a predetermined relation to each other, a switch means at said switch junction comprising a movable switch frog and sensing elements having support means whereby said elements may be disposed to be engaged by respective code pins; connecting cable means whereby engagement of said sensing elements by said code pins effects operation of said switch frog to divert said cart at said switch junction, said cable means comprising a cable having ends attached to respective sensing elements, and said cable extending around a pulley connected to said switch frog and disposed so that bodily movement of said pulley effects movement of saidswitch frog, wherein movement of both of said sensing elements effects said bodily movement of said pulley to move said switch frog and wherein movement of but one of said sensing elements effects rotation of said pulley without bodily movement thereof to prevent movement of said switch frog.

13. In a system as set forth in claim 12, said pulley being carried by an arm and said arm being secured to said switch frog for movement thereof, and detent means to hold said arm in an initial position or a position to which it has been moved.

14. A towline cart switching system having a switch junction and a cart provided with a plurality of code pins and support means therefor whereby said code pins may be disposed in a predetermined relation to each other, a switch means at said switch junction having sensing elements and support means for said elements whereby said elements may be disposed in relation to each other so as to be engaged by respective code pins and having control means whereby actuation of said sensing elements effects operation of said switch means to divert said cart at said switch junction, said control means comprising a respective electrical switch for each of said sensing elements, said electrical switches being connected in series, said switch means comprising a movable switch frog and latch means for latching said frog in a predetermined position, means for biasing said frog to move to another position upon release of said latch means, and electromagnetic means controlled by said electrical switches for motivating said latch means to effect said release responsive to movement of said sensing elements and operation of respective electrical switches thereby.

15. A towline cart switching system having a switch junction and a cart provided with a plurality of code pins and support means therefor whereby said code pins may be disposed in a predetermined relation to each other, a switch means at said switch junction having sensing elements and support means for said elements whereby said elements may be disposed in relation to each other so as to be engaged by respective code pins and having actuating means whereby actuation of said sensing elements effects operation of said switch means to divert said cart at said switch junction, said support means comprising a depressible structure for carrying said sensing elements adjacent the surface of a floor on which said cart moves and having at least one member normally extending above floor level and engageable by said cart to depress said structure, and stop means for limiting the extent of depression so that said member is effectively leveled with said floor to provide support for said cartin moving therepast.

References Cited UNITED STATES PATENTS 3,094,944 6/1963 Bradt 10'4-l72 3,103,183 9/1963 Bradt 104-172 3,174,439 3/1965 Edgar 104172 ARTHUR L. LA POINT, Primary Examiner. D. F. WORTH, Assistant Examiner. 

